I had my first FP+ reservation day earlier this week, so I can certainly sympathize. I made a list of FP that I wanted each day; that list included the people who would do the attraction, when my TP had it scheduled, what my ideal FP window would be, and in some cases, what alternative to do if the FP I wanted wasn’t available (so if FOP was totally gone, I’d do Na’vi instead, or if Kiliminjaro was not available in the mid-morning, the next best time for my TP was the late afternoon).
There was one thing that threw me for a loop. When you pick a date and park, the website will bring you to a screen showing the FP attractions and available times. You can change the time range (morning, afternoon, evening) or pick a time. The thing that I didn’t figure out until halfway through is that there may be times available between the times listed. So, for example, if 12:00, 1:20, and 3:00 are listed, there may be FP available at 12:45. To see all FP available, click the “View Details and More times” link below the attraction name. Not rocket science, but I didn’t notice it. I ended up cancelling lots of the FP I made and redoing them once I noticed that link. (By the way, you can change the FP time using the “modify” tool so that you don’t let go of your old FP until you are securing your new one. You can also change who holds the FP or add people using “change party.”)
You can be making FP in one tab or window and in another have the Disney website show a list of the FP+ reservations made. That helped me keep track of how many FP I had booked for that day and when they were for.
Make sure you have the MDE app downloaded and ready to go on your phone, tablet, etc. Some people have had problems with the website not working right. Disney’s tech people helped them, but it took and hour or two. The app, however, can work for people even if the website has a glitch for them.